Lecture 3 Flashcards
Enteral Nutrition (EN)
General definition:
Nutrition provided through the gastrointestinal (GI) tract via
a tube, catheter, or stoma that delivers nutrients distal to the
oral cavity
encompasses:
– ONS (covered last lecture)
– Tube feeding (focus of today’s lecture)
who needs EN
Patients who are unable to meet their nutritional requirements
(calories, nutrients) or consume adequate nutrition exclusively via an
oral diet.
Common Conditions Where EN Might Be Used
Respiratory failure requiring ventilatory support
– Hypermetabolic states: septic shock, organ failure, trauma, burns
• Disorders (neurological or other) impacting swallowing
– Dysphagia, CVA/stroke, dementia, neurotrauma, decreased LOC
– Cerebral palsy, Myasthenia gravis, multiple sclerosis,
• GI disease
– Inflammatory bowel disease (Crohn’s, colitis), obstructions, pancreatitis
– Peri/post-op surgery (abdominal, oncology etc.)
• Insufficient intake
– Eating disorders, CHF, COPD, cancer, HIV/AIDS, ESRD etc
• Why If the GI tract is functiona we should USE IT!
Maintains functional integrity of the gut
– Maintains normal gallbladder function
• Nutrients in small intestine stimulate CCK release
– Help maintains gut-associated lymphoid tissue (GALT)
• Vital to immune functioning
– Improved clinical outcomes (vs. NPO or PN)
• Less expensive than PN
Contraindications for EN
• Insufficient GI absorptive capacity (i.e. short bowel syndrome or other severe
malabsorption syndromes)
- Mechanical obstruction of the GIT and GIT cannot be accessed
- Paralytic ileus
- Severe GI bleed
- Distal high-output fistula
- Intractable vomiting/diarrhea that doesn’t improve with medical mgmt
- GI tract cannot be accessed (i.e. upper GI obstruction)
• Aggressive nutrition intervention not warranted (i.e. palliation, withdrawal of
life sustaining treatments)
Types of Enteral Tube Feeding (Access)
Nasogastric (NG) tube Orogastric (OG) tube Nasoduodenal (ND) tube Nasojejunal (NJ) tube Gastrostomy tube (G-tube or PEG) Jejunostomy tube (J-tube) Gastrojejunostomy tube (G-J tube or PEG-J)
Factors Influencing EN Access
Expected duration of EN therapy
– Short-term (days, few weeks)-> oro/naso routes
– Longer-term (> 4-6 weeks, years)-> G,J,G-J TUBES
• Clinical factors
– Obstruction, bleeds (i.e. esophageal varicies)etc
• Modality of feeding (timing/feeding schedule)
• Desired location
• Available expertise and resources
– i.e. Skilled clinicians available to insert tubes?
– Equipment availability (i.e. feeding pumps)
Feeding Tube Size
• Tube diameter measured in French units (Fr) (1 French = 0.33 mm)
Small-bore tubes: 5-12 Fr
– More comfortable
– Easier placement into small bowel
– Clogged easily
• Larger bore (> 14 Fr)
• Common tube sizes:
– NG: 8-16 Fr; – NJ: 8-12 Fr
– G-tube: 12-30 Fr – GJ: 6-14 Fr
Standard, polymeric
Contains macronutrients as non-hydrolyzed protein, fat and CHO
Semi-elemental
Contains partially hydrolyzed nutrients (protein) and altered fats to maximize absorption
Elemental
Completely hydrolyzed nutrients to maximize absorption
Blenderized
Mixture of blenderized whole foods, with or w/o addition of standard formula
Disease-specific
Targeted for organ dysfunction or specific metabolic conditions
Elemental & Semi-Elemental Formulae
• Indicated in individuals with impaired digestion/absorption
– i.e. GI disorders, short bowel syndrome, pancreatitis
• Protein
– Free amino acid, dipeptides, tripeptides, oligopeptides
• CHO
– Monosaccharides, dissacharides, glucose oligosaccharides
• Fat
– Medium chain triglycerides (MCT), monoglycerides, diglycerids
Disease Specific Formulae
Formula manipulation
– Macronutrients, micronutrients, electrolytes, minerals, immunoenhancing nutrients
• Examples:
– Diabetes/glucose control, renal, acute respiratory distress syndrome
(ARDS), cardiopulmonary disease, immunosuppression, hepatic disease
etc.
• Efficacy: not always strong evidence base
• Typically ++ expensive
Modality of Feeding: Timing
Continuous feeding
• Pump-assisted continuous drip infusion
• Preferred method for: critically ill, at refeeding risk, poor glycemic control,
J-tube, intolerance to other modalities
• Gravity drip method also continuous (no pump); usually outside of hospital
setting
Cyclic feeding • Provides EN by pump over time period < 24h (i.e. over 12h period)
• Often transition from continuous to cyclic
Intermittent feeding • Delivered by pump or gravity • Larger volumes into stomach over short periods (i.e. 1-3 cups formula over 20-60 min, 4-6x/d) • Mimics meals
Bolus feeding
• Similar to intermittent with fed via syringe and more aggressive, i.e. 240
mL over 4-6 min, 3-6 times per day, mimicking meals
• Provide freedom of movement
Continuous feeding
• Pump-assisted continuous drip infusion
• Preferred method for: critically ill, at refeeding risk, poor glycemic control,
J-tube, intolerance to other modalities
• Gravity drip method also continuous (no pump); usually outside of hospital
setting
Cyclic feeding
- Provides EN by pump over time period < 24h (i.e. over 12h period)
- Often transition from continuous to cyclic
Intermittent feeding
• Delivered by pump or gravity
• Larger volumes into stomach over short periods (i.e. 1-3 cups formula over
20-60 min, 4-6x/d)
• Mimics meals
Bolus feeding
• Similar to intermittent with fed via syringe and more aggressive, i.e. 240
mL over 4-6 min, 3-6 times per day, mimicking meals
• Provide freedom of movement
Choice of modality affected by:
• Choice of modality affected by: – Medical condition/status – Location of tip of feeding tube – Patient’s expected tolerance – Level of care – Equipment availability – Transitions across the care continuum
Steps in Initiation of Enteral Nutrition
1. Assess patient requirements – Kcal, protein, macronutrients, fluids 2. Select appropriate formula – Require a modular? 3. Determine modality (rate) 4. Considerations – Water flushes • Additional fluid needs • Tube patency – Medications • Flush w/ 30-60 mL water pre/post med via tube to reduce risk clogged tube • Drug nutrient interactions; hold feeds 2h pre/post (i.e. Synthroid, Dilantin, Ciprofloxacin)
